THE FOLLOWING SLIDES ARE REVIEW OF HOMEWORK 8-10 (PACKET)

1. THE FOLLOWING SLIDES ARE REVIEW OF HOMEWORK 8-10 (PACKET)

2. a) b) c) d) 1) The four diagrams below model the results of mixing atoms of different substances. Each atom is represented by a different symbol. Which diagram correctly models a chemical change?

3. 2) The table below shows the chemical symbols for common elements. Based on the information in the table, which of the 4 substances below is a compound?  a) CO b) He c) Si d) Fe

4. 3) The diagram below shows a rock sample and an identification key. This rock sample is an example of  an element b) compound c) heterogeneous mixture d) homogeneous mixture

5. 4) Some common substances and their chemical formulas are listed in the chart below Which of these substances are elements?  a) hydrochloric acid b) carbon dioxide and water c) oxygen and helium d) water and oxygen

6. Ans: The ball would not pass through the ring anymore after it was heated because its size changed. 5) The illustration below shows a solid metal ball and a ring before and after heat is applied to the metal ball. Before heat is applied, the metal ball passes easily through the ring. After heat is applied, the metal ball does not pass through the ring. What evidence shows that a physical change took place in the metal ball?

7. a) c) b) d) ***6) Magnets A and B are of equal magnetic strength. In which position will the magnets A and B have the greatest attractive force toward each other?

8. A chemical property of a mineral is evident if the mineral a) breaks easily when struck with a hammer b) bubbles when acid is placed on it c) is easily scratched by a fingernail d) reflects light from its surface

9. Ans: Bubbles start to form 8) Equal–sized pieces of aluminum were placed in test tubes containing equal volumes of acid, at different temperatures. The temperature of the acid is test tube A is 5oC. The temperature of the acid in test tube B is 20oC. What observation would indicate that a chemical reaction is taking place in the test tubes?

10. 10) Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride is formed and hydrogen gas is released. This is an example of a) physical change b) chemical reaction c) homogeneous mixture d) heterogeneous mixture 11) Which one of the following characteristics represents a chemical property? a) Reactivity b) Malleability c) Solubility d) Color e) Melting Point

11. 12) Sand and iron particles that a similar in size and color are mixed together in a beaker. What would be the best method in separating the particles? Use tweezers to separate them b) Use a magnet to separate them c) Add water to separate the mixture d) Pour the mixture into a filter 13) Which action forms a different chemical substance? a) crushing a rock b) burning a piece of wood c) mixing salt and pepper d) melting an ice cube

12. 14) A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change? a) The baseball strikes the roof b) The roof of the car dents c) The paint cracks and chips d) The exposed metal rusts

13. Ans: Bubbles start to form 15) List one observation that shows a chemical change is occurring in the diagram.

14. Salt Sand Water 16) Identify the soluble material, the insoluble material, and the solvent. Soluble material_____________________________________________ Insoluble material: _______________________________________ Solvent: ________________________________________________

15. Ans: The substances are combined with NO chemical change . 17) Explain why the contents of the flask in Figure B are classified as a mixture.

16. Ans: The water evaporated (liquid to gas) . 18) Explain why only solid salt particles remain in the flask in figure C.

17. ***25) The flask and its contents had a mass of 120 grams before the experiment and a mass of 120 grams after the experiment. Which conclusion can best be made from these measurements? a) a phase change took place b) Energy was destroyed c) Matter was conserved d) New elements were formed

18. 26) The chemical change that occurred in the flask is most similar to burning a piece of coal b) freezing water in a container c) breaking a piece of wood into many pieces d) bending a wire to form a hook

19. Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period. Definitions: Atom: lego blocks of all matter Matter: anything that takes up space Element: type of atom Molecule: 2 or more atoms connected at electrons Compound Molecule: molecule with different elements Chemical Reaction (Change): when new molecules are formed Fusion: nuclei of more than one atom combine to form a new element

20. Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period. Definitions: 8) Reactants: molecules/atoms you begin with (left of arrow) 9) Products: molecules/atoms you end with (right of arrow) 10) Physical Change: change in physical characteristic but NO new molecules formed 11) Coefficient: Big # before molecule. Tells am’t of molecules 12) Subscript: lower # in a molecular formula. Tells am’t of atoms 13) Mixture: physical combination of things but NO chemical change

21. Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period. Definitions: 14) Heterogeneous Mixture: mixture where you can see the different substances 15) Homogeneous Mixture: mixture where everything looks the same 16) Solution: homogeneous mixture where something dissolves 17) Soluble: Can dissolve 18) Insoluble: Can not dissolve 19) Solute: The thing dissolving 20) Solvent: the thing that a substance dissolves in

22. Additional Vocabulary: 21) Temperature 22)State of matter 22) Phase Change 23) Condensation 24) Evaporation 25) Sublimation 25) Boiling point 26)Melting point